Pneumatic action for musical instruments



C. V. JAMESON.

PNEUMATIC ACTION FOR MUSICAL INSTRUMENTS. APPLICATION FILED OCT. 10. 1917.

1,353,753, PatentedSept. 21,1920.

2 SHEETS-SHEET I.

' C. \l. JAMESON.

PNEUMATLC ACTION FOR MUSICAL INSTRUMENTS. APPLIQATION FILED 00110. 1917.

1,353,753. PatentedSept; 21, 1920.

2 SHEETS-SHEET 2- I15 5. z/ I z J Zia/ways.

UNITED STATES PATENT OFFICE.

' CHARLES V.. IAMESON, OF CHICAGO, ILLINOIS.

I PNEUMATIC .ACTIO'N FOR MUSICAL INSTRUMENTS.

Application filed October 10, 1917.

T 0 all whom it may concern:

Be it known that 1, CHARLES V. Jameson, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Pneumatic Actions for Musical Instruments, of which the following is a specification.

This invention relates more particularly to the type of pneumatic actions known as unit actions, in which the controlling valves and associated partsof each striker pneumatic constitute a detachable unit which is separate and distinct from the remaining units, facilitating assemblage of the parts and repair and renewal of the valves.

One of the objects of my invention isito increase the rigidity of the wind chest in such a manner as to render it practically self-bracing, thereby dispensing with the customary braces and correspondingly simplifying its construction and reducing its cost of production.

Further objects are to rendera-ll parts of the action readily accessible, to produce a novel construction which affords comparatively large air passages not liable to .become choked by dust and lint, and tocombine with the action simple and compact regulating devices to which access can be easily had without removingor disturbing other parts of the action or instrument.

In the accompanying drawings:

Figure 1 is a fragmentary front. elevation of a wind chest containing the invention. Fig.2 is a fragmentary rear elevation. thereof; Fig. 3 is a transverse section of the action on line 83, Fig. 2, with some of the parts omitted for clearness. Fig. 4 is a fragmentary front view, partly in section, of the channel-board. Fig.5 is a rear View, partly in section, of one of'the valve blocks. Fig. 6 is a sectional bottom plan view thereof. Fig. 7 is a view of the hinged. end of one of the strikenpneumatics.

Similar characters of reference indicate corresponding parts throughout the several views.

1 indicates the keys of a playerpiano, 2 the shank of one of the hammersof the piano action, 3 the wippen, 3 the jack and a the sticker. I

The frame or body of the wind chest shown in the drawings comprises upright Specification of Letters Patent.

Patented Sept. 21, 1920.

Serial No. 195,666.

end pieces or standards 5, a longitudinal basestrip or board 6 connecting the lower portions of said standard and longitudinal upper strips 7, 8 and 9, connecting their upper portions. This frame may however be of any other suitable construction.

In its general or anization, the pneumatic action comprises a nxed upright longitudinal channel board 10, rows of striker pneumatics 11 mounted on the rear side of saic board, and corresponding rows of valve blocks or units 12 mounted on the front side of saidboard. These pneumatics are carried by horizontal channel boards or shelves 13 to the undersides of which their fixed boards are glued or otherwise fastened, in the particular construction shown in the drawings. The upright channel board 10 is suitably fastened to the standards 5 and the strips 6 and 9 and is provided with longitudinal vacuum channels or chambers 14:, one for each row of valve-blocks and the compa-nion striker pneumatic s. The several vacuum channels'communicate at their ends with upright manifold passages 15 which are connected with the usual main exhaust bellows, not shown, by one or more trunks 16, so that said channels 1d are constantly exhausted during the operation of the instrument.

The valve-blocks or units are detachably secured to the channel board 10 by screws 17 or other fastening means. These units may .be of any suitable construction, but that shown in the drawings is preferred. Each block contains a lower vacuum chamber 18 connected by a passage 19 with the corresponding vacuum channel 14 of the board 10, and an upper air or vent chamber 20 connected with the corresponding striker pneumatic 11 by a channel 20 extending transversely through said channel board and the corresponding shelf 13 above the companion passage 19; A vent port 21 connects the chamber 20 with the atmosphere. tains the vacuum port 23. Located in the upper valve-chamber is the usual duplex valve 24, the heads of which cooperate with the vacuum and vent ports 23 and 21 respectively,to open the one when the other is closed and thereby collapse or inflate the corresponding striker pneumatic 11, in a common manner. 25 indicates the customary valve/operating pouchor pneumatic ar- The partition 22 of the block conv rail-35 mounted on the member 9 and having ranged in the lower portion of the block,

and 26 the tube leading from the correspond: ing duct or" the tracker 2.7 to the chamber underneath the pouch.

lnthe preferred construction illustrated in the drawings, the striker pneumatics are directly in line with their companion valve blocks.

and striker p'neumatics. Being set verticallyon edge and comparatively deep and narrow, it possesses the necessary strength and stiffness to avoid sagging or warping thereof; This channel board is thus practically self-bracing, doing away with the 7 separate brace members or blocks required,

for example, in pneumatic actions of the layer type and correspondingly reducing the cost of the wind chest. At the same time, the valve units arejreadily accessible and detachable from the channel board. This construction also permits the use of air pas,- sages of sufiiclent area to guard against choking of the action.

28 indicates thestickers the pneumatic action each of which cooperates with the corresponding wippen 3. Each of these stickers is'preferably bent from a single length of wire. It has the usual button or collar 29 which is engaged 'by the movable board a vertical guide-groove 31 arranged in the rear side of the strip 9. The upper stopmember 32'preferably consists of a vertical screw engaging an opening in a horizontal screws 38 engage openingsin the lower portion of the member 9, or other suitable support just above the channel board 10, and their headed front ends are accessible from the front side of. the pneumatic action through the space left between the uppermost rowof valve-blocks 12'and the strip 7.

By means of the adjusting screws 32 and other parts.

Each of the striker pneumatics is preferably provided with a follow-up spring 40 which tends constantly to swing its movable V board upwardly toward its fixediboard As shown, the channel boardis a single member common to the various valve blocks thereby keeping the movable board in contact with the button of the corresponding sticker and preventing lost motion between these parts when the pneumatic is collapsed. It will be understood that in adjusting the sticker vertically by the screw 33, to bring its shoulder 30 in proper relation to the wippen 3,the button of the sticker would ordinarily be raised and supported by the elbow lever 33,'out of contact with the, movable board of the pneumatic, in which case there would be lost motion between the button andsaidboard and the latter would be relieved from the weight of the sticker or equivalent part of the action. The followup spring 40 is so light as to be overcome by the weight of the sticker, and yet strong enough to constantly raise and press said movable board against the button of the sticker in the expanded or vented condition of the pneumatic. The springthereby affords the advantage of automatically taking up any suchlost motion, and no adjustment thereof is required. this follow-up spring is located at the hingeend of the pneumatic and consists of a piece of spring wire extending obliquely across the hinge-joint with its ends suitably secured to the fixed and movable boards, respectively,

as shownin Fig. 7. This produces a neat,

compact and inexpensive construction.

1 do not wish to claim in this application the unit or valve block 12 as the construction of the same forms the subj ect'of another application for patent filed by me May 24, 1918, Serial No. 236,426.

I claim as my invention l -The combination of a pneumatic, a sticker actuated thereby and having a laterally-extending member provided with a free end portion, and stop-devices arranged above and below said free end portion for limiting the stroke of the sticker.

2. The combination of a pneumatic, a sticker actuated thereby and carrying a finger,'a-lever arranged in the path of movementof said stopmember for limiting'its stroke, and adjusting means for said lever.

3. The combination of a pneumatic, a sticker actuated thereby and carrying a finger, a vertical1y-adjustable stop for limiting the upward strokeof said stop-member, an elbow lever'having one of its arms arranged to limit the downward stroke of said stop-member, andadjusting means engaging the other arm of said lever. v

4:; The combination of an upright channel-board, striker-pneumatics applied to the rear side of said board, corresponding valveblocks applied to the front side of said board, stickers actuated by said pneumatics and having stop-fingers arranged above the striker-pneumatics, adjustable means for limiting the upward stroke of said stopfingers, a row of vertically-swinging elbowlevers, having their upper arms arranged to limit the downward stroke of said fingers, and a horizontal row of adjusting screws arranged above said channel board and engaging the lower arms of said levers, there being a space above the uppermost valveblocks to afford access to said adjusting screws.

5. The combination of a pneumatic, a member having a guide slot, and a sticker actuated by said pneumatic and carrying a laterally-extending guide-member the free end of which is arranged in said slot, said slot being arranged parallel with the sticker and the side walls of the slot holding the guide-member against lateral displacement.

6. The combination of a sticker having a projection, a pneumatic having a movable board engaging said projection to actuate the sticker, and a follow-up spring constantly acting on said movable board to cause it to follow up said projection and prevent lost motion, said spring being light enough to be overcome by the weight of the sticker and yet strong enough to raise said movable board when relieved from the weight of the sticker.

7. The combination of a sticker having a projection, a pneumatic having a movable board engaging said projection to actuate the sticker, and a follow-up spring tending constantly to collapse the pneumatic, said spring extending obliquely across the hingejoint of the pneumatic and connecting its fixed and movable boards.

CHARLES V. J AMESON. 

